fix: correctly validate package/realm path (gnolang#1813)

The regex pattern used for package/realm path validation is incorrect.
Currently, it allows paths with special characters and empty path parts,

Fixed it.

BREAKING CHANGE:
- Special characters are disallowed
- Cannot have trailing slash(s)
- Cannot have empty path part
- Cannot have solely `_`[underscore(s)] in path

tm2/pkg/std/memfile.go

@@ -37,11 +37,9 @@ func (mempkg *MemPackage) IsEmpty() bool {
 	return len(mempkg.Files) == 0
 }
 
-const rePathPart = `[a-z][a-z0-9_]*`
-
 var (
 	rePkgName      = regexp.MustCompile(`^[a-z][a-z0-9_]*$`)
-	rePkgOrRlmPath = regexp.MustCompile(`gno\.land/(?:p|r)(?:/` + rePathPart + `)+`)
+	rePkgOrRlmPath = regexp.MustCompile(`^gno\.land\/(?:p|r)(?:\/_?[a-z]+[a-z0-9_]*)+$`)
 	reFileName     = regexp.MustCompile(`^([a-zA-Z0-9_]*\.[a-z0-9_\.]*|LICENSE|README)$`)
 )
 

tm2/pkg/std/memfile_test.go

@@ -51,3 +51,152 @@ func TestMemPackage_Validate(t *testing.T) {
 		})
 	}
 }
+
+func TestRePkgOrRlmPath(t *testing.T) {
+	t.Parallel()
+
+	testTable := []struct {
+		desc, in string
+		expected bool
+	}{
+		{
+			desc:     "Valid p",
+			in:       "gno.land/p/path/path",
+			expected: true,
+		},
+		{
+			desc:     "Valid r",
+			in:       "gno.land/r/path/path",
+			expected: true,
+		},
+		{
+			desc:     "Leading Underscore",
+			in:       "gno.land/r/path/_path",
+			expected: true,
+		},
+		{
+			desc:     "Trailing Underscore",
+			in:       "gno.land/r/path/path_",
+			expected: true,
+		},
+		{
+			desc:     "Underscore in Between",
+			in:       "gno.land/r/path/p_ath",
+			expected: true,
+		},
+		{
+			desc:     "Invalid With Underscore 1",
+			in:       "gno.land/r/path/_",
+			expected: false,
+		},
+		{
+			desc:     "Invalid With Underscore 2",
+			in:       "gno.land/r/path/_/_",
+			expected: false,
+		},
+		{
+			desc:     "Invalid With Underscore 3",
+			in:       "gno.land/r/path/__/path",
+			expected: false,
+		},
+		{
+			desc:     "Invalid With Hyphen",
+			in:       "gno.land/r/path/pa-th",
+			expected: false,
+		},
+		{
+			desc:     "Invalid x",
+			in:       "gno.land/x/path/path",
+			expected: false,
+		},
+		{
+			desc:     "Missing Path 1",
+			in:       "gno.land/p",
+			expected: false,
+		},
+		{
+			desc:     "Missing Path 2",
+			in:       "gno.land/p/",
+			expected: false,
+		},
+		{
+			desc:     "Invalid domain",
+			in:       "github.com/p/path/path",
+			expected: false,
+		},
+		{
+			desc:     "Special Character 1",
+			in:       "gno.land/p/p@th/abc/def",
+			expected: false,
+		},
+		{
+			desc:     "Special Character 2",
+			in:       "gno.land/p/p&th/abc/def",
+			expected: false,
+		},
+		{
+			desc:     "Special Character 3",
+			in:       "gno.land/p/p&%$#h/abc/def",
+			expected: false,
+		},
+		{
+			desc:     "Leading Number",
+			in:       "gno.land/p/1Path/abc/def",
+			expected: false,
+		},
+		{
+			desc:     "Uppercase Letters",
+			in:       "gno.land/p/PaTh/abc/def",
+			expected: false,
+		},
+		{
+			desc:     "Empty Path Part",
+			in:       "gno.land/p/path//def",
+			expected: false,
+		},
+		{
+			desc:     "Trailing Slash",
+			in:       "gno.land/p/path/abc/def/",
+			expected: false,
+		},
+		{
+			desc:     "Extra Slash(s)",
+			in:       "gno.land/p/path///abc/def",
+			expected: false,
+		},
+		{
+			desc:     "Valid Long path",
+			in:       "gno.land/r/very/very/very/long/path",
+			expected: true,
+		},
+		{
+			desc:     "Long Path With Special Character 1",
+			in:       "gno.land/r/very/very/very/long/p@th",
+			expected: false,
+		},
+		{
+			desc:     "Long Path With Special Character 2",
+			in:       "gno.land/r/very/very/v%ry/long/path",
+			expected: false,
+		},
+		{
+			desc:     "Long Path With Trailing Slash",
+			in:       "gno.land/r/very/very/very/long/path/",
+			expected: false,
+		},
+		{
+			desc:     "Long Path With Empty Path Part",
+			in:       "gno.land/r/very/very/very//long/path/",
+			expected: false,
+		},
+	}
+
+	for _, tc := range testTable {
+		tc := tc
+		t.Run(tc.desc, func(t *testing.T) {
+			t.Parallel()
+
+			assert.Equal(t, tc.expected, rePkgOrRlmPath.MatchString(tc.in))
+		})
+	}
+}